While cladribine shows sustained efficacy through 4 years in trials, real-world evidence beyond this timepoint remains limited, particularly retreatment strategies and age-specific outcomes.

We used data from the Czech national MS registry (ReMuS) and included pwMS who had completed full 2 courses of cladribine by June 30, 2025, with ≥5 years of follow-up. We assessed clinical effectiveness and treatment patterns. Patients were classified as: N (no further treatment), R (retreatment with cladribine), and S (switch to another therapy). We performed exploratory analysis in pwMS aged ≥50.

More than half of pwMS do not require additional treatment 5 years after initiating cladribine tablets, despite not being treatment-naïve. Retreatment appears to be a beneficial strategy, effectively restoring disease control with relapse-free rates increasing from 38% to 85%. PwMS aged ≥50 years showed encouraging patterns consistent with suitability for an exit-strategy subgroup, albeit with interpretation limited by small sample size.